A fuel supply device that supplies a fuel to an engine includes a low-pressure pump feeding the fuel of a fuel tank and a high-pressure pump compressing the fuel discharged from the low-pressure pump and feeding the fuel to the engine. According to Patent Literature 1, in the above configuration, a pressure pulse is generated by the high-pressure pump that is a generation source of the pressure pulse.
In a configuration according to Patent Literature 1, a passage enlarging pipe having a flow passage area larger than that of a fuel gallery of the high-pressure pump is interposed between the fuel gallery and a fuel passage from the low-pressure pump and the high-pressure pump so as to suppress the pressure pulse. In addition, the fuel gallery has an end that is opposite to the passage enlarging pipe and is provided with an overflow valve. In the above configuration, a phase reversal reflection wave that is reflected at a boundary portion between the fuel gallery and the passage enlarging pipe and a phase reflection wave that is reflected at a boundary portion between the fuel gallery and the overflow valve are combined. Thus, the pressure pulse in the fuel gallery is reduced.